1. Field of the Invention
This invention relates generally to a carbide insert which is brazed into a material-moving board or blade and, more particularly, to a carbide insert which is adapted to extend substantially the full width of the board.
2. Description of the Related Art
It is standard in the industry to put an insert, most commonly made of an alloy of tungsten carbide, in the lower edge of a board or blade in order to strengthen it. An example of such an insert is shown in the patent to Stephenson, U.S. Pat. No. 3,529,677. It is noted that this insert does not extend the full width of the board, but instead is only a portion of the width of the board. While such an insert is useful in somewhat reducing the wear on the board, it is also true that part of the metal or other substance making up the board does tend to deteriorate since the board still is in contact with the ground. Because the board is typically made of a softer material than the insert, it tends to wear away from the insert and the insert then falls out and the board itself must be replaced.
The reference to Stephenson et al., U.S. Pat. No. 3,934,654, takes a step in correcting this problem. It is noted that in this reference, the carbide insert is shaped such that a larger portion of the insert is touching the ground and a much smaller portion of the board touches the ground. Such a system will help to a certain extent in reducing the wear on the board. However, where the board touches the ground there will still be wear and the board will wear away from the insert causing the insert to fall out and requiring replacement of the board.
The patent to Adrian et al., U.S. Pat. No. 5,427,186, shows a different method for reducing wear on a board. However, this insert correlates primarily to wear which would occur on the front edge of a board. The problem of the board wearing away from touching the ground still remains.
A similar problem was addressed in the patents to Ferreira, U.S. Pat. Nos. 5,471,770 and 5,611,157, where a rubberized wear pad is attached to the bottom of a board. The primary purpose in this system is to prevent wear to a road from the use of the board. Of less concern is damage to the board itself. The wear pad will have some effect in keeping the board from deteriorating, however in many applications such a pad will deteriorate rapidly and require frequent replacement. However, such a system is not effective for each application, since in many instances it is desirable that a metal rather than a polyurethane edge be used.
Those skilled in this art have failed to solve the problem of providing an insert structure which adequately protects the material-moving board from rapid wear, is readily adaptable to conventional boards, is itself significantly resistant to wear erosion to provide a sufficient useful life, and which may be more securely attached to the board to resist premature separation from the board.